Hiroyoshi Ishida

Sonotubometric Measurement of the Eustachian Tube Function by Means of Band Noise

The Eustachian tube is well known as an organ serving the ventilation and drainage of the tympanic cavity and mastoid. Ventilation is carried out by the opening and closing of the Eustachian tube accompanying swallowing movements. Until now there has been no instrument to quantify these motor activities of the tube necessary for its function as a ventilator. The author developed a generally applicable sonotubometer Model WIO-01 with the help of Siemens Hearing Institute K.K. for automatic measurement of the aforesaid tubal function with the use of 7 kHz full-octave band noise. In a sonotubometric trial with 32 adult female subjects, the duration of patency of the Eustachian tube was 288.5 +/- 1.38.5 ms, and the amplitude eliciting response was 16.4 +/- 8.3 dB. The positive response rate was 89.1%. In 89 children aged 4-12 years, a positive response was detected in 117 ears (61.9%). The mean duration of patency was 337.7 +/- 154.4 ms, and the amplitude 16.3 +/- 7.2 dB. It is physiological to have tubal opening and closing during natural swallowing. It is therefore important to understand the tubal function when dealing with tympanoplasty and diseases caused by tubal dysfunction.

Ethyl Loflazepate in the Treatment of Tinnitus

Ethyl loflazepate (Meilax®) was administered orally to 91 patients suffering from tinnitus, 58 with tinnitus and sensorineural hearing loss, 27 with tinnitus without hearing loss, and 6 with tinnitus accompanied by sudden deafness. The clinical severity of tinnitus was evaluated every two weeks in terms of loudness, continuity and annoyance. Medication was rate of as effective in 27.5%, moderately effevtive in 33%, slightly effective in 17.6% and not effective in 21.8% at the end of treatment. Effectiveness depend on the duration of treatment. Patients treated for a relatively long period showed greater clinical improvement. Two patients complained of sleepiness as a side effect. It was concluded that ethyl loflazepate is effective in reducing severity of tinnitus.

Hyperbaric therapy of otitis media in children.

Secretory otitis media occurs most frequently in infancy. Since the Eustachian tube functions differently in children and adults, it is considered unlikely that secretory otitis media in the two age groups is due to the same cause. Since the infantile Eustachian tube is a kind of pressure open type, we preffered high-pressure therapy in the treatment of secretory otitis media in children.We used high-pressure therapy for 111 children aged 3 to 12 years 188 ears) with secretory otitis media. As a result, 129 ears(68.6%)showed improved average hearing levels within 10 dB in the low, medium, and high tone ranges. No patient experienced earache or other trouble when exposed to high-pressures. In the highpressure therapy, air escapes through the Eustachian tube when the middle ear pressure is regulated. In this case, the fluid can be excreted together with the air. Since the partial pressure of oxgen rises with the pressure, it is estimated that the highpressure therapy favorably affects ciliary movement and restores the mucous menbranes in the tympanic cavity and the Eustachian tube.

A posturological study of pseudofistular sign in normal adults and Meniere's patients

A new stabilographical method with pressure loading to the external auditory canal (PLT) was performed in 20 normal subjects and 3 patients with Menieres disease for the purpose of testing the pseudofistular sign. The pressure ranging from -100mmH2O to +100mmH2O or from -200mmH20 to +200mmH2O were applied to the external auditory canal and the body sways of the center of gravity to the lateral directions for 10 seconds were summated 10 times by a signalprocessor (NEC-sanei, 7TO7A). Positive response was defined as having doubles sway amplitude compaired with the average amplitude of sway without pressure loading.Positive response were observed in seven of twenty normal subjects. These positive reactions were symmetrical in both ears except one case. On the other hand, in cases of Menieres disease, positive responses were found only in the affected ears. The positive PLT response was not changed at all when the test was repeated in a case of Menieres disease at the stage of positive response to the grycerol test, however, in another case of Menieres disease, disappearance of positive PLT response was observed after the puncture of the eardrum.From these findings we considered that the most effective facter of the PLT in producing the deviation was not the pressure change of the middle ear, but the movement of the ossicular chain causing displacement of the foot-plate of stapes.

Correlation between Personality and Vestibular Dysfunction

Among 1300 patient with vestibular dysfunction surveyed epidemiologically, 843 were analysed as to personality type with disorder reference to vestibular and to subjective vertigo.(A) Correlation between Disease and Personality1) Few patients had a strong-minded or strong-willed personality.2) Strong-willed personality was apt to be present in patients suffering from traumatic dysfunction of the vestibular system.3) A social personality traits were often found in patients suffering from true Menieres disease, suspected Menieres disease, and advanced bilateralvestibular dysfunction.(B) Correlation between Subjective Vertigo and Personality1) In general, no differences in degree of subjective vertigo were observed among patients with different personality traits.

Observation of the Velocity of Body Sway Ménière's Disease

Vestibulo-spinal reflexes in Menieres disease were analyzed using gravigrams and velocitygrams.Studies of vestibular disturbance have so far been centered around nystagmus. With the development of the gravicorder, however, a new approach to the testing of vestibulospinal reflexes began to be tried, which is based on the analysis of the center of gravity.A characteristic of gravigrams is that they are positional graphs and provide no information about time-course changes in the velocity with which the center of gravity moves. To clarify time-course changes in the velocity of the sway of the center of gravity while recording its movement, we processed data of the change in the time-course velocity, a component of dynamic control system, with a computer and obtained velocity-grams.On gravigrams, body movements differing in frequency are represented by the same area change as long as their amplitudes are the same. These same body movements, however, produce completely different velocitygrams, which are constructed on the basis of differentials of the above recordings.Eleven patients with Menieres disease were then tested during a non-attack period with their eyes open and closed. It became clear from the above test that, even among patients who exhibited the same pattern of area change on gravigrams, velocitygrams were different from each other. This means that the velocity is controlled by a different recovery conditions.That the velocitygrams of patients in a non-attack period varied greatly suggests that each patient responded differently to treatment.The above findings indicate that the velocity of body sway, which is a parameter of the dynamic control functions, plays an important role in the clinical diagnosis of equilibrium disturbance.

Implications of the Results of Stepping Test in Patients with Unilateral Vestibular Dysfunction

The stepping test is a dynamic test for the evaluation of equilibratory function, whose accuracy is so high that it enables us to detect even a slightly compensatory stage labyrinthine disturbance undetectable with static equilibratory function tests. Because it is a equilibrium movement test, it requires a more precise adjustment of the pyramidal and extrapyramidal systems. A stepping test with eyes closed allows us to record and observe even a slightest disturbance of the pyramidal and extrapyramidal tract that cannot be demonstrated with static equilibratory function tests. In patients with unilateral labyrinthine disturbance, a deviation occurs during the stepping test. No publication is available, however, that deals with the time course change in the stepping record.We recorded the center of gravity in the stepping test by KINETOGRAVICORDER and studied time-course change in the recording. Our findings were as follows:Nine patients with unilateral Menieres disease (in normal phase), selected as subjects, were instructed to face front in the dark. In that position, they performed steppings in an exact rhythm (1.2Hz) with eyes closed, while recordings were taken to examine the onset of deviation. Deviation started with the 8th to 17th step (average 12.4th step), or 6.4sec to 13.6sec (average 9.95sec) after the initiation of steppings.The above results suggest that: (1) A voluntary movement due to central programming is eliminated by approximately about 12 steppings to be replaced by an extrapyramidal reflex. The period during which the said 12 steppings or thereabouts are performed (about 10sec) is the latent time for deviation, (2) a regular rhythm accelerates the manifestation of laterality in the motor reflex, (3) the imposition of regular rhythm has an element of the Jendrassik maneuver, so that it encourages the manifestation of deviation in steppings. We concluded therefore that the stepping test would yield sufficiently meaningful data even if the number of steps to be taken was reduced from that in the past test.